In the video, the water level was 15 milliliters before adding the chain, and 20 milliliters after adding the chain. when i weighed the chain, its mass was 76.3 grams. i believe the chain is solid metal (not gold plated), but is probably a blend of gold and other metals. i looked up that gold has a density of 19.3 g/ml, while the other metals like silver and copper usually blended with gold have a combined density of about 9.7 g/ml. determine what percentage of the chain is gold, by mass, to at least 1 decimal place?

39.7%

Step-by-step explanation:

1. First find the density of your chain

Density = mass / volume

Volume = displaced water volume

                     = Volume of Final level of water - initial level of water

                    = 20 ml - 15 ml = 5 ml

Mass = 66.7 g

Density = 66.7g / 5 ml = 13.34 g/ml

2. Second, write the denisty of the chain as the weighted average of the densities of the other metals:

Mass of gold × density of gold + mass of other metals × density of other metals, all divided by the mass of the chain.

Calling x the amount of gold, then the amount of other metals is 66.7 - x:

Then, there are 26.47 grams of gold in 66.7 grams of chain, which yields a percentage of:

(26.47 / 66.7) × 100 = 39.7%1. First find the density of your chain

Density = mass / volume

Volume = displaced water volume

                     = Volume of Final level of water - initial level of water

                    = 20 ml - 15 ml = 5 ml

Mass = 66.7 g

Density = 66.7g / 5 ml = 13.34 g/ml

2. Second, write the denisty of the chain as the weighted average of the densities of the other metals:

Mass of gold × density of gold + mass of other metals × density of other metals, all divided by the mass of the chain.

Calling x the amount of gold, then the amount of other metals is 66.7 - x:

Then, there are 26.47 grams of gold in 66.7 grams of chain, which yields a percentage of:

(26.47 / 66.7) × 100 = 39.7%

d

step-by-step explanation:

given

y + 3 = - 4(x - 2) ← distribute the parenthesis

y + 3 = - 4x + 8 ( subtract 3 from both sides )

y = - 4x + 5 → d

in problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. to find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.

hope it